Section 198. Every railroad corporation having a terminus in Boston shall furnish such number of workingmen’s trains, not less than two each way, as the department, upon a petition for such trains filed with it, shall in each case order. Such trains shall arrive at Boston between six and half past seven o’clock in the morning and leave Boston between the same hours in the evening and special cars may be provided therefor. Season tickets, good once a day each way for six days in the week, shall be furnished for such trains at a rate not exceeding, for yearly tickets, three dollars a mile, and for quarterly tickets, one dollar a mile.